Known sound absorbing elements are often designed as double-wall systems. Such double-wall systems as a rule consists of two wall areas that are connected to each other, spaced apart, by way of mechanical connections. Above all, when the double-wall systems for reasons of space must be thin, the sound absorbing measures of known double-wall systems in particular in the low-frequency range are relatively modest. In this case, the two wall areas of the known double-wall systems are coupled to each other in the most unfavourable manner by way of the air that is trapped between the wall areas, wherein in addition, coupling by way of the necessary mechanical connections takes place, as a result of which sound from the one wall area may also be transferred to the other wall area. As a result of this design, known double-wall systems, however, result in only modest sound absorbing measures, a situation which appears, however, in particular in the area of aircraft and space technology, to be inadequate with a view to passenger comfort.
Further state of the art includes an insulation glass unit, disclosed in DE3014207C2, with an interior pane, an exterior pane and a gas filling in the clear space. At least one of the rims of at least one of the panes is held, by means of a sprung end unit, in a dislocatable manner so as to oscillate when exposed to sound. In the central region, the spring function of the end unit comprises an substantially horizontal section, along which the operating point of the end unit travels when subjected to sound.